Why Congenitally Blind People Show Activity in Visual-Processing Areas of the Brain - Neuroscience News

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Summary: Study reveals structural changes of connectivity successful the thalamus to different encephalon areas successful those with congenital blindness, providing grounds of encephalon plasticity. The areas of the thalamus that link with the occipital lobe successful those with blindness are weaker and smaller, giving abstraction to connections successful the temporal cortex which are strengthened.

Source: IDOR

Recently published successful the technological journal Human Brain Mapping, a Brazilian survey has identified for the archetypal clip the reorganization of anatomical structures successful the encephalon of radical with congenital blindness.

The probe was carried retired by the D’Or Institute of Research and Education (IDOR), the Federal University of Rio de Janeiro (UFRJ), and the Center for Specialized Ophthalmology, Brazil.

A fewer decades ago, technological studies reported the funny find that radical calved unsighted could activate the vision-processing portion of the brain, the occipital cortex, erstwhile engaging successful a non-visual activity, specified arsenic speechmaking successful Braille (a tactile connection system).

These studies were further grounds of the alleged encephalon plasticity, which is the brain’s quality to reorganize its connections to look adversity. This process tin impact a bid of structural modifications, specified arsenic processing caller neural pathways oregon reorganizing existing connections.

“Soon aft we are born, we are exposed to stimuli captured by our senses, which are cardinal to find the brain’s circuitry. It is besides a clip successful which our encephalon is successful large transformation.

“Technically we could deliberation that the occipital cortex would beryllium functionless successful radical who were calved blind, but we cognize that this is not the case. It is activated. What we lacked to recognize was the structural process down it,” explains Dr. Fernanda Tovar-Moll, corresponding writer of the existent survey and president of IDOR.

In the research, magnetic resonance imaging techniques were utilized to analyse structural connectivity successful the quality encephalon and to analyse the anticipation of alternate neural connections. The neural images of 10 individuals with congenital blindness and Braille readers were compared to a power radical of 10 individuals with intact vision.

After elaborate analysis, the scientists observed structural changes of connectivity successful the thalamus, a operation located successful the diencephalon, the cardinal portion of the encephalon that receives, processes, and distributes accusation captured by the main quality senses – specified arsenic vision, hearing, and interaction – to the antithetic encephalon regions.

“Plasticity has been the probe absorption of our radical for galore years now, and successful this lawsuit of cross-modal plasticity successful congenitally unsighted people, successful which distant areas of the encephalon contiguous this communication, we suspected that the improvement would beryllium originating successful the thalamus, arsenic it is the encephalon operation liable for connecting respective cortical regions, and it could beryllium an country that with small alteration successful the axonal circuitry [part of the neuron liable for conducting electrical impulses] would beryllium capable to link cortices that were distant from 1 another”, comments the neuroscientist.

This shows a exemplary of a caput and brain

The probe besides observed that the country of the thalamus dedicated to connecting with the occipital cortex (vision) was smaller and weaker successful unsighted individuals, giving abstraction to connections with the temporal cortex (hearing), which were shown to beryllium strengthened erstwhile compared to those observed successful individuals without ocular impairment. This means that successful summation to being activated, the ocular cortex is besides invaded by connections that refine different senses, specified arsenic proceeding and touch.

It was the archetypal clip that a survey described in humans an alternate mapping successful the connectivity of the thalamus with the occipital and temporal cortices, and these integrative reorganizations whitethorn beryllium a mechanics susceptible of explaining however non-visual stimuli scope and activate the ocular cortex successful congenitally unsighted people.

“Neuroimaging studies let america to navigate the operation of the encephalon and amended recognize the diverseness of encephalon plasticity, which tin besides pave the mode for discoveries specified arsenic caller ocular rehabilitation initiatives”, adds Dr. Tovar-Moll, informing that her probe radical is inactive progressive successful different studies with congenitally unsighted radical successful which they investigate, successful summation to the structure, the functional adaptations of encephalon plasticity successful this population.